I. Field of the Disclosure
The technology of the disclosure relates generally to operational amplifiers, and particularly to calibrating operational amplifiers in light of offset voltages.
II. Background
An operational amplifier (also referred to as an “op-amp”) is a device that receives differential input signals and generates an output voltage based on a gain of the op-amp. A wide variety of circuit functions may be accomplished using op-amps, and thus, op-amps are employed in a vast array of electronic devices. However, process variations in the manufacturing of internal components of an op-amp may generate unintended internal offset voltages that change the output voltage. In this manner, the output voltage of an op-amp is calculated by multiplying a gain of the op-amp by a sum of the voltage difference of the differential input signals and any such offset voltage present. For example, an op-amp receiving a first differential input voltage V1 and a second differential input voltage V2, and having an offset voltage VOFFSET, generates an output voltage VOUT equal to A*(V1−V2+VOFFSET), where ‘A’ represents the op-amp's gain. Thus, the offset voltage VOFFSET may increase or decrease the output voltage VOUT of the op-amp.
Variations in the output voltage VOUT of an op-amp attributable to an offset voltage VOFFSET of the op-amp may delay or cause errors in other elements of a circuit that employ the op-amp. In this manner, an offset voltage VOFFSET of an op-amp may cause reduced performance of circuits designed with a low tolerance for variation in an output voltage VOUT of an op-amp. Therefore, it would be advantageous to employ op-amps such that effects of an offset voltage VOFFSET on an output voltage VOUT of an op-amp are reduced or avoided.